[libc++] s/_VSTD::is_unsigned/is_unsigned/ in <random>. NFCI.

Author: Quuxplusone

libcxx/include/random

@@ -1919,7 +1919,7 @@ private:
 
     static_assert(__m == 0 || __a < __m, "linear_congruential_engine invalid parameters");
     static_assert(__m == 0 || __c < __m, "linear_congruential_engine invalid parameters");
-    static_assert(_VSTD::is_unsigned<_UIntType>::value, "_UIntType must be unsigned type");
+    static_assert(is_unsigned<_UIntType>::value, "_UIntType must be unsigned type");
 public:
     static _LIBCPP_CONSTEXPR const result_type _Min = __c == 0u ? 1u: 0u;
     static _LIBCPP_CONSTEXPR const result_type _Max = __m - 1u;

libcxx/test/std/numerics/rand/rand.eng/rand.eng.lcong/params.fail.cpp

@@ -24,7 +24,7 @@ int main(int, char**)
     // expected-error@random:* {{static_assert failed due to requirement '1ULL == 0 || 1ULL < 1ULL' "linear_congruential_engine invalid parameters"}}
     std::linear_congruential_engine<T, 0, 1, 1> e3;
     std::linear_congruential_engine<T, 1, 0, 1> e4;
-    // expected-error-re@random:* {{static_assert failed due to requirement 'std:{{.*}}:is_unsigned<int>::value' "_UIntType must be unsigned type"}}
+    // expected-error@random:* {{static_assert failed due to requirement 'is_unsigned<int>::value' "_UIntType must be unsigned type"}}
     std::linear_congruential_engine<int, 0, 0, 0> e5;
 
     return 0;